Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: Infection parameters in C57BL/6J and Pdcd1 −/− mice immunized with rBCG-N-RSV (A) C57BL/6J mice were immunized intradermally with a 2-dose schedule (0 and 14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. (B) Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. Both groups were challenged with RSV 7 days after the booster, and euthanasia was performed at 7 dpi. (C–F) body weight changes relative to day 0 for (C) C57BL/6J mice, (D) C57BL/6J mice treated with Nivolumab, (E) Pdcd1 −/− mice, and (F) combined comparison of RSV-infected groups from different mice genotypes and treatments. (G-H) Viral load, represented as the copy number of N-RSV per 5000 copies of β-actin, was quantified by RT-qPCR in lung homogenates of each group. Data are presented as mean ± SEM from two independent experiments with three mice per group ( n = 6). (C-F) Multiple comparisons were performed using a mixed-effects model followed by Dunnett’s post hoc test. (G and H) two-way ANOVA followed by Bonferroni’s multiple comparisons test was applied. p < 0.05 was considered statistically significant for both statistical analyses used for this figure. p values shown in blue indicate comparisons made exclusively against the mock group.

Article Snippet: Nivolumab , Opdivo TM , Bristol Myers Squibb , N/A.

Techniques: Infection, Comparison, Quantitative RT-PCR

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: Effect of PD-1 blockade and ablation on follicular CD4 + T cells and T cell memory differentiation in vaccine mice C57BL/6J mice were immunized intradermally with a 2-dose schedule (0–14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. Memory compartment cells and CD4 + follicular T cells were also analyzed by flow cytometry in splenocytes extracted from rBCG-N-RSV-immunized mice after 72 h of stimulation with N-RSV protein (10 μg/mL) (A) Gating strategy (B) Change in the number of follicular CD4 + T cells. (C) Percent of Memory CD4 + T cells. (D) Percent of Memory CD8 + T cells. Naive: CD62L + CD44 − , TCM: CD62L + CD44 + , and TEM: CD62L − CD44 + . Data represent the mean ± SEM of two independent experiments with three mice per group ( n = 6). (B) Kruskal-Wallis’s test was applied for multiple group comparisons, followed by Dunn’s post hoc test. (C and D) Mixed-effect analysis followed by a Bonferroni test was used for multiple comparisons. p < 0.05 was considered statistically significant for both statistical analyses used for this figure.

Article Snippet: Nivolumab , Opdivo TM , Bristol Myers Squibb , N/A.

Techniques: Flow Cytometry

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: IFN-γ and IL-17 responses in rBCG-N-RSV–immunized mice under PD-1 modulation C57BL/6J mice were immunized intradermally with a 2-dose schedule (0–14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. The splenocytes (3 × 10 5 cells/well) from mice were stimulated with N-RSV protein (10 μg/mL) for 72 h, and (A) IFN-γ- and (B) IL-17-producing SFCs were quantified by ELISPOT. (C) Representative ELISPOT images are shown in the last panel. Data represent the mean ± SEM of two independent experiments with three mice per group ( n = 6). Kruskal-Wallis’s test was applied for multiple group comparisons, followed by Dunn’s post hoc test. p < 0.05 was considered statistically significant.

Article Snippet: Nivolumab , Opdivo TM , Bristol Myers Squibb , N/A.

Techniques: Enzyme-linked Immunospot

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: Changes in humoral immune response induced by the vaccine C57BL/6J mice were immunized intradermally with a 2-dose schedule (0–14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. Both groups were challenged with RSV 7 days after the booster, and euthanasia was performed at 7 dpi. (A) Neutralizing antibodies and (B) total anti-N-RSV IgG levels and (C) avidity percentage in serum were determined. Data represent the mean ± SEM of two independent experiments with three mice per group ( n = 6). two-way ANOVA followed by a Bonferroni test was used for multiple comparisons. p < 0.05 was considered statistically significant.

Article Snippet: Nivolumab , Opdivo TM , Bristol Myers Squibb , N/A.

Techniques:

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: Infection parameters in C57BL/6J and Pdcd1 −/− mice immunized with rBCG-N-RSV (A) C57BL/6J mice were immunized intradermally with a 2-dose schedule (0 and 14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. (B) Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. Both groups were challenged with RSV 7 days after the booster, and euthanasia was performed at 7 dpi. (C–F) body weight changes relative to day 0 for (C) C57BL/6J mice, (D) C57BL/6J mice treated with Nivolumab, (E) Pdcd1 −/− mice, and (F) combined comparison of RSV-infected groups from different mice genotypes and treatments. (G-H) Viral load, represented as the copy number of N-RSV per 5000 copies of β-actin, was quantified by RT-qPCR in lung homogenates of each group. Data are presented as mean ± SEM from two independent experiments with three mice per group ( n = 6). (C-F) Multiple comparisons were performed using a mixed-effects model followed by Dunnett’s post hoc test. (G and H) two-way ANOVA followed by Bonferroni’s multiple comparisons test was applied. p < 0.05 was considered statistically significant for both statistical analyses used for this figure. p values shown in blue indicate comparisons made exclusively against the mock group.

Article Snippet: Immunized and nonimmunized five to eight-week-old male C57BL/6J mice received two weekly doses (100 μg nivolumab (Opdivo TM , Bristol Myers Squibb) intraperitoneally (i.p.) injection throughout the protocol described in Figures A and A. Additionally, a non-immunized RSV-challenged group received two weekly doses of a 100-μg isotype control (GoInVivo, BioLegend).

Techniques: Infection, Comparison, Quantitative RT-PCR

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: Effect of PD-1 blockade and ablation on follicular CD4 + T cells and T cell memory differentiation in vaccine mice C57BL/6J mice were immunized intradermally with a 2-dose schedule (0–14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. Memory compartment cells and CD4 + follicular T cells were also analyzed by flow cytometry in splenocytes extracted from rBCG-N-RSV-immunized mice after 72 h of stimulation with N-RSV protein (10 μg/mL) (A) Gating strategy (B) Change in the number of follicular CD4 + T cells. (C) Percent of Memory CD4 + T cells. (D) Percent of Memory CD8 + T cells. Naive: CD62L + CD44 − , TCM: CD62L + CD44 + , and TEM: CD62L − CD44 + . Data represent the mean ± SEM of two independent experiments with three mice per group ( n = 6). (B) Kruskal-Wallis’s test was applied for multiple group comparisons, followed by Dunn’s post hoc test. (C and D) Mixed-effect analysis followed by a Bonferroni test was used for multiple comparisons. p < 0.05 was considered statistically significant for both statistical analyses used for this figure.

Article Snippet: Immunized and nonimmunized five to eight-week-old male C57BL/6J mice received two weekly doses (100 μg nivolumab (Opdivo TM , Bristol Myers Squibb) intraperitoneally (i.p.) injection throughout the protocol described in Figures A and A. Additionally, a non-immunized RSV-challenged group received two weekly doses of a 100-μg isotype control (GoInVivo, BioLegend).

Techniques: Flow Cytometry

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: IFN-γ and IL-17 responses in rBCG-N-RSV–immunized mice under PD-1 modulation C57BL/6J mice were immunized intradermally with a 2-dose schedule (0–14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. The splenocytes (3 × 10 5 cells/well) from mice were stimulated with N-RSV protein (10 μg/mL) for 72 h, and (A) IFN-γ- and (B) IL-17-producing SFCs were quantified by ELISPOT. (C) Representative ELISPOT images are shown in the last panel. Data represent the mean ± SEM of two independent experiments with three mice per group ( n = 6). Kruskal-Wallis’s test was applied for multiple group comparisons, followed by Dunn’s post hoc test. p < 0.05 was considered statistically significant.

Article Snippet: Immunized and nonimmunized five to eight-week-old male C57BL/6J mice received two weekly doses (100 μg nivolumab (Opdivo TM , Bristol Myers Squibb) intraperitoneally (i.p.) injection throughout the protocol described in Figures A and A. Additionally, a non-immunized RSV-challenged group received two weekly doses of a 100-μg isotype control (GoInVivo, BioLegend).

Techniques: Enzyme-linked Immunospot

Journal: iScience

Article Title: Regulation of antiviral immunity by PD-1 during respiratory syncitial virus infection and upon vaccination

doi: 10.1016/j.isci.2026.116157

Figure Lengend Snippet: Changes in humoral immune response induced by the vaccine C57BL/6J mice were immunized intradermally with a 2-dose schedule (0–14 days) of rBCG-N-RSV and treated intraperitoneally with 100 μg of nivolumab twice a week throughout the protocol. Simultaneously, another group of Pdcd1 −/− mice received the same immunization schedule. Euthanasia was carried out 14 days after the booster. Both groups were challenged with RSV 7 days after the booster, and euthanasia was performed at 7 dpi. (A) Neutralizing antibodies and (B) total anti-N-RSV IgG levels and (C) avidity percentage in serum were determined. Data represent the mean ± SEM of two independent experiments with three mice per group ( n = 6). two-way ANOVA followed by a Bonferroni test was used for multiple comparisons. p < 0.05 was considered statistically significant.

Article Snippet: Immunized and nonimmunized five to eight-week-old male C57BL/6J mice received two weekly doses (100 μg nivolumab (Opdivo TM , Bristol Myers Squibb) intraperitoneally (i.p.) injection throughout the protocol described in Figures A and A. Additionally, a non-immunized RSV-challenged group received two weekly doses of a 100-μg isotype control (GoInVivo, BioLegend).

Techniques: